Leukotriene Receptors

Abstract

Leukotrienes are metabolites of arachidonic acid catalyzed by a novel lipoxygenase specific for the C-5 position. These fatty acids have many pharmacological properties including smooth muscle contractions and leukocytes activation, and are believed to play a key role in inflammatory and hypersensitivity reactions. Experimental evidence suggests that the action of leukotrienes is mediated by specific receptors. In this paper pharmacological and biochemical data in favor of the existence of leukotriene receptors are presented and hypotheses on the mechanisms of action and transduction are discussed.

Leukotriene C4 modulation of muscarinic K+ current activation in bullfrog atrial myocytes.

“…Activation of cardiac LTC4 receptors causes changes in cardiac contractility under conditions in which conversion of LTC4 to LTD4(LTE4) is prevented and alterations in cell Ca 2+ or IP3 are not observed Chiono, Heller, Andazola, and Herman, 1991). LTC4 binding is not affected by GTP (Hogaboom, Mong, Wu, and Crooke, 1983;Mong, Wu, Scott, Lewis, Clark, Weichman, Kinzig, Gleason, and Crooke, 1985;Cristol et al, 1989), suggesting that the receptor does not belong to the G protein-coupled superfamily.…”

“…Binding sites for LTC4 are widely distributed (Cristol et al, 1989), although a biological activity associated with LTC4 binding is not always apparent. Careful analysis of LTC4 binding sites suggests that some apparent LTC4 "receptors" may represent cytoplasmic enzymes such as glutathione transferase (Sun, Chau, Spur, Corey, Lewis, and Austen, 1986;Sun, Chau, and Austen, 1987).…”